For most of Sunday’s game against the Tampa Bay Buccaneers, 13-time Pro Bowl tight end Tony Gonzalez served as an effective 6-foot-5 decoy.

With Atlanta wide receivers Julio Jones and Roddy White out with injuries, Gonzalez figured to be Matt Ryan’s favorite target against the Bucs, but Harry Douglas stole the spotlight.

While Gonzalez was limited to two catches for 30 yards, Douglas torched Tampa Bay’s secondary in the opening half with six receptions for 140 yards, including a 37-yard touchdown when he got behind rookie cornerback Johnthan Banks.

“Harry had a career day,’’ Falcons coach Mike Smith said. “Harry’s role changed two weeks ago because of our situation at wide receiver. He stepped up to the plate and did an extremely good job today. He was the No. 1 receiver in the game.’’

En route to only his second career 100-yard effort, Douglas also hauled in a 54-yard pass against cornerback Leonard Johnson as Ryan finished with a career-high 148.4 passer rating.

“Harry played a great game,’’ said Ryan, now 34-2 when he registers a passer rating of 100.0 or higher. “I don’t think anyone in that locker room was surprised with the way he played.’’

All week long, Bucs coach Greg Schiano said Tampa Bay’s secondary couldn’t afford to go to sleep on Atlanta’s receiving corps just because White and Jones would be inactive.

“We knew Douglas was the third receiver,’’ Bucs cornerback Darrelle Revis said. “He had a great game today.’’

Ominous start

The game was only three minutes old when Bucs quarterback Mike Glennon looked every bit like a rookie making his first NFL road start.

Tampa Bay’s initial possession ended disastrously as Glennon fumbled when hit by blitzing William Moore, with fellow safety Thomas DeCoud picking up the ball and dashing 30 yards to give the Falcons a quick 7-0 advantage.

“They blitzed me and I was looking for my hot guy,’’ said Glennon, who was sacked three times. “I wasn’t able to get it to him, but that’s on me. I have to hold on to the ball. No one else is to blame but myself, but I am going to get that corrected.’’

Moore came free up the middle and forced the turnover as he was dragging Glennon down to the ground.

“It was a great play call by (defensive coordinator) Mike Nolan,’’ Moore said. “They had a young quarterback in the game and we decided to send a little pressure toward him and see how he adjusted.’’

Record-setting afternoon for Jackson

For the second consecutive week, Bucs wide receiver Vincent Jackson put up big numbers in defeat.

Targeted on half of Mike Glennon’s 44 pass attempts, Jackson finished with 10 receptions for 138 yards and two scores. He made a one-handed grab on a 59-yard touchdown in the second quarter and added a 1-yard scoring catch that pulled Tampa Bay within 24-17 in the third quarter after Brian Leonard forced a fumble during Robert Alford’s punt return.

“We’re playing hard to the end, but once again, it’s self-inflicted wounds that are hurting us,’’ said Jackson, the first Buccaneer to post consecutive 100-yard receiving games since Antonio Bryant in 2008.

Jackson, who caught nine passes for 114 yards and two touchdowns last week against Philadelphia, is the first player in franchise history with back-to-back games of at least 100 receiving yards and two touchdown catches.